Valve



May 12, 1931. I G. A. ROBERTSHAW 1,804,438

VALVE F'iled July 13, 1927 v IVENTORII' v yi'w dra a. 12, "1 931 UNITEDSTATES,

PATENT OFFICE ononen A. aonnmsmw, or omnsnuxo, rmsrnvnm VALVEApplication filed July 18,

1 effects of the fluid being handled thereby.

It is customary at the resent time in the art to which the resentinvention relates-to construct control valves, "of the characterutilized for the handling of gases, of a nonferrous material, usuallybrass. A good grade of brass having a high copper content as been foundto corrode rapidly, probably due to a sulphide deposit which builds upthereon. a

l have found that relatively less expensive grades of brass, ordinarilyreferred to as yellow brass, and having a relatively low copper contentas compared to red brass, resist corrosion due to fuel gases much betterso than does red brass having the high co per content. It will beunderstood that'in both red and yellow brass the actual copper contentis higher than the zinc content. g

Due to the general-porous characteristics of a casting formed fromyellow brass and having the usual low copper and high zinc content, ithas heretofore not been considered feasible to produce valve bodiesentirely therefrom; This has necessitated the use of red brass eventhough it is more expensive and is subject to" greater corrosion.

The present invention has for one of its ob iects the provision otanimproved valve body having not only the desired non-porouscharacteristics required for the utilization thereof with permeablefluids, and more particularly gas, but also of such nature thatcorrosion is reduced to a minimum.

lln the accompanying drawings, there are shown more or lessdiagrammatically for purposes of illustration only, certain embodimentsof the present invention, it being understood that the drawings do notdefine the Fig. l is a vertical sectional view through ferrous seat. Themoisture content corresponding to the limits of my invention, as changesin the con- 1927. Serial R0. 205,481.

one form of valve constructed in accordance with the present invention;and

Fig. 2 1s a view similar to Fig. 1 illustrating another embodiment ofthe invention.

' It has heretofore been proposed in the art to effect, a solution ofthe problem involved by the utilization ina non-ferrous body of a ingases, however, has resulted in ObjGCtlOIlable'rusting of the ferrousmaterial in such present manner that continued proper seating of thevalve has not been possible.

Referring more particularly to Fig. 1 of the drawings, there isillustrated a valve body 2 of suitable construction and of any desiredcharacteristics, dependin ular use to which it is to he put. This bodyis preferably constructed of red brass having the low zinc and highcopper content referred to, due to the necessity of providing anonporous construction.

The body is formed with a countersunk seat 3 and with a second similarcountersunk seat t, preferably in. concentric relation to the firstseat. Cooperating with these seats are tubular valve seats 5, preferablytermihating at their 11 per edges in a common plane to provide a ouble,seat for cooperation with a single disc valve, not shown, as wellunderstood in the art.

The valve seats 5 are preferably constructed of yellow brass having thehigh zinc, low copper content, due to their greater corrosion-resistingproperties.

In Fig. 2 of the drawings there is illustrated a similar. constructionembodying, however, a single valve seat. In Fig, 2 parts arts of Fig. 1previously described in etail are designated by the same referencecharacters having a prime afixed thereto.

In first attempting to produce a valve in accordance with the presentinvention, I provided a preformed yellow brass ring-shaped valve seatand attempted to cast a red brass body thereaE-round. Due to the fact,however, that yellow brass melts at a temperature of approximatel t00less than the melting point of red rass, such an operation necessarilyresults in a large percentage of loss upon the particdue to thedestruction of the yellow brass valve seat during the casting operation.

It is, of course, possible in accordance with the present invention tothread the seats in the valve body and thereafter thread the valve seatsinto position. Such an operation, however, entails extra machine yvorkand unless great accuracy exists there is a possibility of leakagethrough the threads. Therefore, while the present invention contemplatesthe utilization of yellow brass rings secured in position by eithercasting or threading,-it is of more particular importance commerciallyin connection with the following method of inserting the valve seats.

This depends upon a pressing operation,

and more particularly upon the utilization of valve seat rings formedfrom comparatively light gauge tubes, it having been found that extremeaccuracy was essential in the utilization of heavy gauge yellow brass.By utilizing light gau e tube rings and forcing them into place underpressure, it is possible to provide a seat in the valve body having aninternal diameter as much as ten thou sandths of an inch smaller thanthe outside diameter of the valve seat rings, the flexibility of therings permitting them to c0nform tothe dimensions and contour of theseat. Not only is accurate machine work 0bviated, but the production ofa. finished valve having accurately formed seats tightly secured inosition frictionally by reason of the flexibi ity of the tube rings, isobtained in this manner.

tions, the proportion of copper in the valve body bein greater than theproportion of copper in t e valve seat.

2. As an article of manufacture, a red brass valve body having a yellowbrass valve seat in position therein.

3. As an article of manufacture, a valve body having a countersunkportion therein and a resilient metallic seat in engagement with saidcountersunk portion and of greater normal diameter than the diameter ofsaid countersunk portion, said seat comprising a section of light gaugeyellow brass tube.

4. As an article of manufacture, a metallic, non-ferrous value bodyhaving a metallic non-ferrous tubular seat of resilient light gaugeyellow brass tube pressed into position therein and maintained in fixedrelation to said body by friction irrespective of whether the valve isopened or closed.

The resulting structure also provides a a raised seat without thenecessity of extra machining. The provision of a seat above thesurrounding portion of the valve body is of distinct advantage as thecountersunk channel on opposite sides thereof serves to collect dirt orother foreign particles.

The present invention also lends itself ad mirably to the production ofknife edges on the yellow brass valve seats, as clearl indicated in thedrawings, thereb obviatlng the necessity of providing such knife edgeson the valve discs as has heretofore been customary.

Certain advantages of the present invention arise from the provision ofa valve body of non-porous nature and of non-ferrous characteristics,whereby it is immune to the moisture content of gases, in combinationwith an accurate separately formed valve seat, or seats, of non-ferrousnature and not subject to the corrosive action of gases, and especiallythe sulphides of manufactured gases.

I claim:

1. As an article of manufacture, a brass valve body having a brass seattherein, the materials of said valve bod and seat both containing copperbut in dl fierent propor-

